Something fishy might be happening on Mars.

NASA’s Perseverance Rover captured an image on the Red Planet of two separate boulders, which seem to resemble a shark fin and a crab claw.

The car-sized robot arrived on Mars on Feb. 18, 2021, and has been exploring the Jezero Crater, looking for any sign of possible human life. But these weirdly shaped boulders were an unexpected surprise.

Perseverance is currently traversing across an ancient river delta that was once a 16,000-foot-deep lake.

The photos, which were taken on Aug. 18, 2023, are an example of the phenomenon of pareidolia.

Pareidolia is when the brain creates a meaningful image from what our eyes see that isn’t reality — such as when the face of Jesus Christ appears on a piece of burnt toast.

It’s far from the first time something on Mars has been the subject of pareidolia.

One of the most famous examples of the phenomenon is the “Face on Mars,” in which an image taken by NASA’s Viking 1 spacecraft in July 1976 appeared to show a sculpture of a face with eyes, a nose and a mouth. NASA explained that the illusion was a result of shadows, but the face certainly sparked debate.

NASA posted the image of the shark fin and crab claw-looking boulders on X (formerly Twitter), as part of their Image of the Week series.

“This rocky duo was spotted hanging out together in a wind-swept area. I spy a…crab claw? Shark fin?” the tweet said. “Comment below with what you see!”

Many people in the replies also saw the underwater animal, but others saw visuals such as a coffee bean, a Stegosaurus, a pair of lips and a turtle head.

Even though Mars was once engulfed with water billions of years ago, there’s no evidence that the now-desolate planet ever had any sea creatures, and these photos don’t change that.